Foams, such as polyurethane (PU) foams, are widely used as fabric backings for seats, such as for vehicle interior materials in the transportation industry. The foams are adhered to the backs of textile face materials. These foam backed composites have a cushion effect which can offer comfort or a luxurious feel in contact areas.
Polyurethane foam is widely used as cushioning material for seats. However, the polyurethane foam backed material can emit volatile substances, which may contribute to ‘fogging’ of vehicle or housing interiors and can furthermore include critical substances, which may negatively affect human health. Furthermore the foam itself may oxidize over time leading to a color change in the material. Recyclability is also an issue which has to be addressed.
For these and other reasons, there is a continued need for another material that would provide cushion properties similar to the ones of foam materials at similar costs. One class of materials which would be suitable for use in seat cushions is nonwovens, for example polyester nonwovens. These materials can provide a suitable backing to many face fabrics and address some of the needs which are difficult to address with conventional PU foam cushions.
Methods of producing mats of perpendicular laid, thermally bonded nonwovens, including air laid and “Struto” nonwoven techniques, have strived to provide a cushion with an economical and weight advantage to previous nonwoven technologies. Many of these techniques orient the staple fibers into a vertical position in a two-dimensional layer. By joining plural such pre-formed mats, a fiber cushion body may be formed.
Another technique for manufacturing a three-dimensional fiber cushion body includes inserting loose fiber material into a three-dimensional mold and supplying heat to the fibers inserted into the mold to cause thermal cross-linking. At least a fraction of the fibers may be oriented so as to predominantly align with a preferential before heat is supplied to effect thermal cross-linking. Such techniques have the advantage that a great variety of three-dimensional shapes may be formed. However, the costs required to produce molds may impose constraints on the number of different mold geometries which may be available and, thus, on the number of three-dimensional fiber cushion geometries which may be produced in the molding process.